I don't recall a waterslide from them, but they used to give you both a logo sticker with clear background sized appropriately for the headstock, and an opaque sticker sized as a bumper sticker whenever you bought a neck or body. Today, you get neither. But, the smaller sticker wasn't used for headstocks very often because unlike a waterslide, it was too thick and would be very difficult to embed in a finish, and they wouldn't do it for you when they finished the neck, either. So, you'd have to stick it on the surface of the wood (or finish), and it just looked tacky/amateurish. As has been pointed out, "partscasters" aren't held in high regard to begin with, so a half-assed sticker didn't help matters much.
They do have the embossed Warmoth emblem available again for a few bucks, and that actually looks pretty good because there's no carrier for it. The letters themselves are individually adhesive and somewhat three dimensional. If you want to declare your instrument's pedigree, that's a decent way of doing it.